In magnetic disk devices, media scanning is usually performed in a user environment. For example, for serial advanced technology attachment hard disk drive (SATA HDD the media scan includes an Auto Offline Scan and a Drive Self Test Extended in which host computer performs a read test to detect the presence or absence of a sector defect in track unit for all of the user area at the idle time when the host computer does not issue any command.
The capacity of the HDD is increasing year by year, and it is thought that it takes several hours to complete the media scan for consumer use, and in the large capacity HDD for Nearline use, it will take dozens of hours in the future.
A channel is one of the parts which consume a lot of power of the HDD. The power consumption of the channel is increased mainly at the time of reading (Read), and the power consumption during the media scan in which reading is performed continuously is also increasing.
For the host computer, in the idle time when performing nothing, the reading processing with large power consumption is performed for all sectors for dozens of hours until the whole scanning is completed, raising the power consumption. When full scan is performed by performing a skip every other track, since the time required for scanning is shortened, the power consumption is lowered. However, there is a problem of missing defects generated in the skipped track.
An object of an embodiment of the present invention is to provide a disk device and a media scanning method capable of reducing power consumption required for media scanning and improving defect detection accuracy.